1. Field of the Invention
The claimed invention generally relates to displays and, more particularly, to a display apparatus capable of displaying a three-dimensional video signal on a display unit.
2. Description of the Related Art
Recently, various types of three-dimensional video display apparatuses, which can enable a user to recognize a two-dimensional video as a three-dimensional video by utilizing optical illusions based on parallax, have been discussed. As a method of displaying a three-dimensional video, an active shutter method is known. In the active shutter method, a viewer wears glasses having shutters, and a video for the right eye and a video for the left eye are alternately displayed. The shutters are controlled so that the eyes can view only the respective videos. As another method of displaying a three-dimensional video, a polarization method is also known. In the polarization method, a right-eye video and a left-eye video are alternately displayed on every other line on a display, and the lines displaying the right-eye video and to the lines displaying the left-eye video are differently polarized. The glasses are also polarized correspondingly. In this way, each of the right and left eyes recognizes a different video. There is also a method utilizing spectroscopy instead of polarization. In addition, as a method of enabling a user to view a three-dimensional video with naked eyes, a parallax barrier method is known. In the parallax barrier method, a slit barrier is provided on the front side of the display, and each of the right and left eyes recognizes a different video. In addition, a lenticular method is also known. In the lenticular method, many minute lenses are provided on the front side of the display, and each of the right and left eyes recognizes a different video.
In addition, display apparatuses capable of displaying both two-dimensional videos and three-dimensional videos are also known.
For example, Japanese Patent Application Laid-Open No. 2004-109330 discusses a mobile phone including a display unit capable of displaying a three-dimensional image. The mobile phone switches a three-dimensional image display screen to a two-dimensional image display screen according to a key operation other than number keys including # and * keys, a call key, a mail key, and a camera key.
However, an issue remains with these display apparatuses capable of displaying both two-dimensional and three-dimensional videos. For example, when a display apparatus outputs a three-dimensional video signal to an external apparatus, if the display apparatus and the external apparatus use different three-dimensional video display methods, a user cannot simultaneously and accurately view a three-dimensional video displayed by the display apparatus and the external apparatus. This is inconvenient when, for example, the user alternately executes an operation of a personal computer (PC) capable of displaying a three-dimensional video and a check of a video displayed on a large-screen television (TV) connected to the PC. According to the above described conventional technique, a user key operation is used as a trigger to switch the two-dimensional display and the three-dimensional display. However, if a user needs to simultaneously view or alternately check a video displayed on a plurality of display apparatuses capable of displaying three-dimensional videos, it is troublesome to operate each of the display apparatuses.